Elastic polyester resins made of certain ordered block copolymers are disclosed in U.S. Pat. Nos. 3,023,192 and 3,954,689.
U.S. Pat. No. 4,013,624 discloses elastomeric properties obtained in polyesters having branched chain compounds in their structure.
U.S. Pat. No. 3,890,279 relates to polyesters having side chains therein.
U.S. Pat. No. 4,254,001 relates to elastomeric copolyester resins which can be made into films, fibers, and molded products.
U.S. Pat. Nos. 3,763,109 and 3,766,146 relate to copolyesters having long chain ester units and short chain ester units therein.
None of the above prior art patents discloses elastomeric copolyester resins which have been made utilizing chain branching agents to produce a high melt strength resin which are capable of being extrusion blow-molded. Moreover, the elastomeric copolyesters of the present invention contain significant amounts of polyalkylene groups within the polymer chain.